The health benefits of moderate-vigorous physical activity are well-established across the lifespan and progress is being made to help Americans achieve the 2008 Physical Activity Guidelines for Americans of 150 minutes/week of moderate-vigorous physical activity. However, Physical Activity Guidelines also state the need to minimize the amount of time spent being sedentary for extended periods; yet adults spend an average of 7.5 h/day being sedentary (i.e., sitting). Our preliminary studies suggest reallocating just 30 min/day from sedentary to light-intensity physical activity, holding moderate-vigorous physical activity constant, can significantly improve health risks. The workplace is the ideal context to reduce sedentary behavior given that American workers spend 70-80% of their workday sitting at a desk. Indeed, our preliminary studies suggest that small but cumulative changes in posture and light-intensity physical activity can be achieved without interfering with daily tasks and productivity. Strategies to reduce sitting and increase light-intensity physical activity in the workplace have been promising but are limited by small sample size, short duration, and non- randomized designs. This project aims to test the relative efficacy of two interventions in 24 worksites across two states (N=720 workers). The MOVE intervention is a multilevel individual, social, environmental, and organizational intervention targeting increases i light-intensity physical activity in the workplace. The STAND&MOVE intervention is the MOVE intervention in addition to the installation and use of sit-stand workstations to reduce sitting an enhance light-intensity physical activity opportunities. Our primary outcome will be objectively-measured changes in light-intensity physical activity and sitting over 12 months, with additional process measures at 6 months and longer-term sustainability outcomes at 24 months. Our secondary outcome will be cardiometabolic risk using a composite measure of fasting glucose, insulin, triglycerides, HDL-cholesterol, and blood pressure over the same time points. Unique features of this application are the group-randomized design, which to our knowledge has yet to be used to test the efficacy of sit-stand workstations in the adult workforce, precise measurement of workplace posture and activity, geographical and workplace diversity across two states (Arizona and Minnesota), diverse investigator team of exercise physiologists, wellness professionals, epidemiologists, and biostatisticians, and strong potential for immediate dissemination and broad implementation due to the real-word setting and high level of generalizability. This project stands to be the most definitive study to date on the efficacy and effectiveness of multi-level workplace interventions to increase light-intensity physical activity, reduce sitting, and improve cardiometabolic health.